Each column uses a different method for specifying what to include and what to exclude.  Here are some examples.

Categories allow you to pick from a customized list:

Text columns are filtered with either exact or inexact matches:

Checkbox columns are either checked or not-checked:

Numeric columns are filtered using typical arithmetic comparison operators:

Date columns use special relational operators:

Date-range columns can be specified using the special date-range control:

Color columns are specified by color ranges:

Height and spread are specified with the special dimension control:

All columns without filtering criteria are shown in the list with a blue symbol.  Any columns used for filtering are shown with a red symbol.  In this example, the �Water� column is set to include only specimen with watering needs equal to Dry, Moist, Wet, or Well drained.